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AMASA COBBS, O F PITTSBURG, PENNSYLVANIA. Letters Patent No. 60,834, dated January 1,1867; antedated December 19,1866.

PHOTOGRAPHIU BATH.

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TO ALL WHOMIT MAY CONCERN:

Be it known that I, AMASA 008138, of Pittsburg, in the county of Alleghany, and State of Pennsylvania, have invented new and useful improvements in Silver or Nitrate Bath for Photographers; and I do hereby declare that the following is a full, clear, and exact ,description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which 4 Figure 1 is a vertical longitudinal section of my improved nitrate bath, and showing, the oscillating bottom, the dipper, and, in red lines, the negative plate inplace.

Figure 2 is a top or plan view of the same, with the cover removed, to show the oscillating bottom and dipper.

The object of my invention is to obviate some of the difliculties heretofore encountered by photographers in silvering negative plates, arising from the streaking of the same from the irregular evaporation of the ether and alcohol, upon immersion in the nitrate bath; and also to prevent any sediment that may be in the bottom of the bath from being stirred up by the immersion of the negative plate; and consists of a box made of wood, ware,,glass, or other suitable material, having an oscillating bottom, and a dipper for immersing the plate in the bath, and removing it when coated.

The box A may be made of wood, ware, glass, or other suitable material; said box A is provided with a cover, 13, which maybe secured to the box by dowelling, or many other manner that will form a close joint. The bath is made with an opening. 0, in one end, near the top, through which the negative plate D may be introduced and removed. The inner edges of the opening G are rounded oii, as represented in the drawings, for convenience in introducing and removing the dipper E andplate D. The oscillating bottom F is pivoted at a little distance from the middle of the box, on the side towards the end in which the opening C is-mad'e, so that when at rest the bottom may take the position shown in fig. 1. When the box is made of wood the oscillating bottom may be pivoted by the projectingends of the strip G attached to said bottom, as represented in the drawings, or by pins projecting from the side edges of the bottom, working in the bottom of grooves H in the sides of the box A. But if the box is made of glass or ware. which I prefer, I pivot the bottom upon a V-shaped projection on its under side, working in a groove or channel across the bottom of the box A, to prevent the bottom F from having a sliding movement when oscillating. I make the dipper in the form represented in the drawings; that is, having the part near the outer end or handle so curved that while said handle shall project from the opening 0, themain part of the dipper will lie along the upper surfaceoi' the bottom F, which can be oscillated by meansof the said dipper E. Upon the lowerends of the branches I of the dipper arc two-projections, J, whichare grooved on their sides, as represented in thedrawings. The negative plate D is placed upon the dipper E, with its lower edge resting in the grooves in the sides of the projections, as shown. The dipper and plate are then lowered into the bath through the opening C, through which they are also removed when the coating of the plate is completed.

Among the advantages of my invention may be mentioned that it tends to prevent the streaking of the plate while in the solution; that it prevents the solution from becoming soiled; that the plate can be easily and quickly placed in the bath and removed therefrom; that the ether and alcohol-can evaporate equally from all parts of the plate, thus facilitating the process of coating; and that the bath can be easily warmed in cold weather'when required.

I claim as new, and desire to secure by Letters Patent The combination of the oscillating bottom F ,-with the box A, in a nitrate bath, substantially as described and for the purposes set forth.

AMASA GOBBS. Witnesses:

Jos. SNOWDEN, Homes S. Snownnn. 

